1. Field of the Invention
The present invention relates to a semiconductor device that carries out input/output of information by wireless communication, and particularly relates to a circuit arrangement and a wire connection structure thereof.
2. Description of the Related Art
A semiconductor device having a wireless communication function is called an ID tag, an IC tag, an IC chip, an RF (Radio Frequency) tag, a wireless tag, or an electronic tag, depending on its use. Among semiconductor devices of such use, one in which a communication circuit or a memory is structured by a semiconductor integrated circuit is also called a wireless chip.
A structure of a wireless chip includes an interface, a memory, a control portion, and the like. As the memory, a random access memory (hereinafter also referred to as “RAM”) capable of writing and reading, and a read only memory (hereinafter also referred to as “ROM”) only for reading are used separately according to a purpose. Specifically, a memory area is assigned for every particular application, and access privilege is managed for every application and every directory. In order to manage access privilege, the wireless chip includes a verifying means which compares with a private code of an application, as well as a control means which gives a user access privilege to the application when the private code is matched as a result of comparison and verification by the verifying means (refer to Patent Document 1: Japanese Published Patent Application No. 2003-16418).
Such a wireless chip is formed from a silicon wafer, and an integrated circuit of a memory circuit, a arithmetic circuit, and the like are formed over a circuit side of a semiconductor substrate (refer to Patent Document 2: Japanese Published Patent Application No. 2000-11129).
The wireless chip formed from a silicon wafer is in a face-down state and connected to an antenna. For example, a chip formed over a flexible substrate has a bump as a contact terminal, and is connected in a face-down state to an antenna provided over another substrate (refer to Patent Document 3: Japanese Published Patent Application No. H8-88586). Alternatively, by applying pressure to a semiconductor element over which a bump is formed, the bump connects to a wiring sheet by pressure in a face-down state (refer to Patent Document 4: Japanese Published Patent Application No. 2000-151057).
When a card to which such a wireless chip is mounted (a so-called IC card) is compared to a magnetic card, the IC card has advantages of having a large memory capacity and high authenticity, as well as advantages that it can be equipped with a arithmetic function, and that it is extremely difficult to falsify. Consequently, it is employed by local governments and the like, and it is suitable for managing personal information.